In the art of preparing containers for filling with beverages and food stuff, it is normal to subject the containers to washing solution projected at the containers under pressure so as to dislodge and remove foreign matter. Devices have been provided for container washing in which jets of washing solution under pressure have been created to thoroughly wash the interior and exterior of the containers. The jets of washing solution are normally intermittent so as to reduce the power required to generate the washing solution sprays and avoid chocking the container while obtaining an air/liquid scrubbing action. One said system is disclosed in Nekola U.S. Pat. No. 3,111,131 of Nov. 19, 1963, the showing being directed to the application of poppet valves and cam driven rocker members.
Another arrangement for controlling the flow of a fluid material under pressure is shown in Guckle U.S. Pat. No. 2,827,928 of Mar. 25, 1958 in which a rotary valve operates to distribute fluid material through a series of outlet ports in an intermittent stream, but because the fluid material is not supplied under an extremely high pressure there appears to be little need for considering the destructive effect generally associated with water hammer.
The prior art also includes the teaching in the U.S. Pat. No. of Herold 2,655,929 of Oct. 20, 1953 which is directed to apparatus for cleaning bottles by the rapid and forcible injection of large volumes of cleaning liquid through the mouth of the bottles, and concurrently directing a counterbalancing stream of fluid against the exterior of the bottles so as to avoid displacing the bottles from the carriers moving the bottles through the cleaning machine. In this patent a hollow cylindrical control valve is provided with a series of diametrically opposite outlet ports for simultaneously releasing pressure fluid in order to effect the counterbalancing action of an external jet of fluid opposing an internal jet of fluid.
The disclosure in Yendley U.S. Pat. No. 3,136,324 of June 9, 1964 is directed to container rinsing apparatus in which a series of fluid flow passages in a housing are sequentially put into communication with a fluid supply channel of helical configuration formed in the periphery of a rotor so that jets of fluid can be created to travel at the speed of the containers for continuous jetting rather than intermittent jetting.
A more recent rotary valve arrangement is disclosed in Babunovic et al. U.S. Pat. No. 3,952,925 of Apr. 27, 1976 wherein the water hammer or shock produced upon quick shut off of the flow of pressure fluid is absorbed by a pressure responsive collapsible flexible wall bladder.
These examples of the prior art are not particularly suitable for the high speed container cleaning apparatus in current use, and it has been found necessary to improve the cleaning function by creating a rapid series of jets at a considerably higher frequency than is found to be possible with the means available in the prior art. The increase in the need for high speed jets of pressure fluid has been obtained in the present rotary valve through controlling water hammer by providing means to maintain a minimum uninterrupted flow at all times during the opening and closing of the principal fluid passages at high speed.